The invention relates to a method for laying floor coverings on sub-floors.
Until the forties of the twentieth century houses were conventionally built with heavy solid stone and heavy wooden beam floors. Their great weight and this type of construction of the residential dividing walls and residential dividing floors guarantee adequate sound insulation. The "heavy" construction was replaced at the end of the forties by lighter construction materials and solid floors (concrete floors). The requirements of footfall sound-proofing are largely not achieved by these building materials according to DIN 4109. Therefore, in the case of normal solid construction, the use of a floating screed (for example a cement screed of at lest 45 mm on a standardised, soft springy sound-insulating foundation between the concrete floor and screed sheet according to DIN 18 164, Part 2: synthetic foam materials--sound-insulating materials for footfall sound-proofing and DIN 18 165, Part 1: fibrous sound insulating materials--sound-insulating materials for footfall sound-proofing) represent the rule of the technology.
Adequately high sound-proofing is achieved by this two-sheet system. The basis of the sound-insulating materials according to DIN 18 164 and DIN 18 165 is represented by polystyrene, rubber, mineral fibres and the like, in which case contacts of sounds conducted through solids to the structure must be avoided above all in the wall connection region.
The footfall sound-proofing index TSM to be expected with floating screeds is composed of the sound-proofing index of the rough floor (equivalent footfall sound-proofing index TSM.sub.eq) and the footfall sound improvement index resulting from an improvement measure and is determined according to the following equation: EQU TSM=TSM.sub.eq +VM-2 dB
The footfall sound-proofing index TSM is calculated according to the equation: EQU TSM=63 dB-L.sub.s,w
L.sub.s,w is the equivalent evaluated standard footfall sound level of the rough floor.
The footfall sound-proofing index is measured acoustically as a footfall sound reduction according to DIN EN 20140 (former DIN 52210). The sound level is in this case measured in decibels (dB).
The known footfall sound improvement measures are:
single-sheet wooden beam floor with intermediate filling PA1 two-sheet floors, i.e. insulating layers between the covering for walking on and wooden beams and cladding on the under side PA1 floating screed with insulating materials having the lowest possible dynamic rigidity of the insulating materials PA1 wooden floorboards laid in a floating manner with a TS-insulating layer PA1 springy supports PA1 walls and floor with a large weight per square meter PA1 low-noise installation elements/insulation between the installation and building work carried out consequently PA1 drawing-in of an sub-floor with spring attachment on the sub-floor PA1 Basement floors (laundry rooms, drying rooms) PA1 Residential dividing floors PA1 Floors above/below open garages, passageways PA1 Floors below attics.
Sound insulation to prevent the transmission of footfall sound is required in:
The inhabitants of apartments should be protected from the transmission of noise from other apartments.
Therefore, good sound insulation should enable the occupants of a house or apartment to develop their own personalities to the full in their own four walls, without the neighbours becoming the unintentional witness to every daily comment. For an apartment's dividing floor, up to the end of the eighties, there was a minimum requirement for a footfall sound-proofing with the footfall sound-proofing index TSM=0 dB. According to DIN 4109 (sound-proofing in building construction), November 1989 issue and the Association of German Engineers Guideline 4100: Sound-proofing of apartments, an increased footfall sound-proofing index TSM is required. The relationship between the noise level and evaluated standard footfall sound level (and at the same time footfall sound-proofing index) is shown approximately by FIG. 1.
In the DIN-standard 4109, November 1989 Issue, for the first time values were given for the necessary footfall sound-proofing of stairs in multi-storey apartment building. In this case, requirements for an evaluated standard footfall sound level of 58 dB (footfall sound-proofing index of 5 dB) were fixed. However, in the long term, the increased evaluated standard footfall sound levels L'.sub.n,w (footfall sound-proofing index TSM) recommended for the transmission of footfall sound should be aimed at, as is apparent from the following table:
Necessary footfall sound-proofing reduced sound-proofing sound-proofing to be aimed for Column 1 2A 2B 3A 3B sound-proofing L'.sub.n,w *) (TSM)*) L'.sub.n,w *) (TSM)*) Lines step in dB in dB in dB in dB 1 I 58 (5) 53 (10) 2 II 53 (10) 46 (17) 3 III 46 (17) 39 (24) *) Between TSM and L'.sub.n,w the following relationship exists: TSM = 63 dB - L'.sub.n,w.
The minimum requirements of the evaluated building-sound-proofing index and the footfall sound-proofing index for important structural components of apartment blocks are reproduced in the Table 1.5, columns 3 and 4, DIN EN 20140 T3. The DIN-standard 4109 furthermore includes minimum requirements for further structural components for increased sound-proofing as well as guidelines for sound-proofing in the specific residential and working area. Worldwide, millions of apartments from early years of construction require renovation. There is also an enormous need to catch up on renovation. In the course of these measures, the continuously increasing requirements as regards sound-proofing must also be taken into consideration. The achievement of a footfall sound-proofing measure is only possible due to additional measures on the rough concrete floors and/or the wooden beam constructions. In the discovery of the footfall sound-proofing of floor constructions, only the floating screed and possibly laid foundations for floor coverings should be included in the calculation, however not soft springy upper floor coverings, since these can be exchanged by the user at any time and their degree or improvement does not remain constant on account of the wear which occurs.
The subject matter of DE 197 31 485 A1 is a method for laying floor coverings on sub-floors, in which for the sub-floors, one mixes a primer known per se (for example from DE-OS 26 26 126) in the form of a dry mortar mixture based on Portland cement, aluminous cement and calcium sulphate (expanding cement of type K), which is suitable for the formation of an Ettringit phase, with 2, 3, 4, 5-tetrahydroxyadipic acid as the liquefier in a quantity of 0.15 to 1.0 percent by weight and a mixture of latexed ground hard fibres, aminoacid polycondensation fibres and polyurethane foam in a quantity of 10 to 20 percent by weight, in each case with respect to the total dry mortar mixture, and one elastifies the dry mortar obtained in this way with a saponification-resistant dispersion of a butadiene-styrene-copolymerisate containing carboxyl groups, with extremely low emission values in a quantity of 4 to 8 percent by weight, in each case with respect to the total dry mortar mixture, one dilutes the mixture obtained with water, applies it to the sub-floor and allows it to dry and then one applies to the rapid-setting thin-layer screed obtained in this way having an improved footfall sound-proofing index (TSM), a low-emission (max. 300 .mu.g/m.sup.3), solvent-free synthetic resin dispersion with a water content of not more than 15 percent, with a content of a tackifier, based on natural resin ester and/or synthetic resins and with a content of an emulsifier based on sulphated and/or sulphonated hydroxy-octadecene acids and/or their high molecular triglycerides of 1 to 5 percent by weight, with respect to the synthetic resin dispersion, in which case the tackifier is adjusted to a pH-value of 4 to 6 and then one lays the covering thereon.
Now it was found that in place of part of the latexed, ground hard fibres, glass fibres, polymerisate fibres, such as polyacrylonitrile, polyamide, polyester or polypropylene fibres, or mixtures thereof, can be used s the fibre components of the dry mortar.
Furthermore, it was found hat due to the fact that the mortar mixture diluted with water, applied to the sub-floor and left to dry, is roughened in the dry state and in this way the filler/fibre mixture is set free from the casing constituted by the cement mortar, a purely mechanical carpet fixing can be achieved, if the carpet covering is laid on the screed treated in this way and rubbed lightly. The sticking of screed and carpet covering deemed necessary hitherto can be dispensed with and if necessary the floor covering can be removed more easily.
Furthermore it was found that the fibres can also be used outside the screed and in this case sticking is also superfluous.